This application is based on patent application No. 2000-393816 filed Dec. 25, 2000 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a printed board connector capable of being mated with a male connector such as an insulation displacement plug having a cable, a contact of the printed board connector and a mating instrument. In particular, the present invention relates to improvements in the prevention of deterioration of electrical conductivity and spring property of contacts resulting from solder rising and/or flux rising which may occur when a printed board connector is mounted in a printed circuit board of electronic equipment by soldering.
2. Description of the Related Art
In electronic equipment such as cellular telephones, a mating instrument composed of an insulation displacement plug (male connector) and a printed board connector (female connector) is often used to connect two power cables of a speaker, a vibration motor, or the like, to a printed circuit board. In this case, the two power cables are fixed by insulation displacement to the insulation displacement plug respectively. The insulation displacement plug with the cables is mated with the printed board connector mounted in the printed circuit board.
With reference to FIGS. 4 to 7, conventional techniques for this kind of connectors will be described.
FIG. 4 is a plan view of an insulation displacement plug 10. FIG. 5 is a sectional view of a conventional printed board connector 20. Also, FIG. 6 shows that the insulation displacement plug 10 and the printed board connector 20 are mated with each other. FIG. 7 is a conventional contact included in the printed board connector 20.
As shown in FIG. 4, the insulation displacement plug 10 includes a plug main body 11 and a pair of insulation displacement contacts 12. The plug main body 11 is made of an insulated material and has a generally rectangular shape. The insulation displacement contacts 12 are arranged in the plug main body 11. The insulation displacement contact 12 has a base portion 13, a pair of side walls 14 extending from the base portion 13, and a contact portion 15 extending substantially in parallel with the respective side walls 14. The pair of side walls 14 have slots 16 formed therebetween. Terminals of cables 17 are pressed in the slots 16. This press-in process removes a part of sheathing 17a of each cable 17 to allow a core 17b of the cable 17 to come into contact with the corresponding side walls 14. Each contact portion 15 is exposed from the plug main body 11 and extends along the corresponding side wall of the plug main body 11. The contact portion 15 is engaged with the corresponding contact of the printed board connector 20.
The printed board connector 20 is mounted at a predetermined location of the printed circuit board. As shown in FIGS. 5 and 6, the printed board connector 20 includes a housing 22 having a chamber 21. The above described insulation displacement plug 10 is fitted into the chamber 21 of the housing 22. Each side wall of the housing 22 has a recess 23 that receives the corresponding contact portion 15 of the insulation displacement plug 10. Also, each side wall of the housing 22 has a contact 24 fixed thereto by press-in. The contact 24 is generally L-shaped as shown in FIG. 7. That is, the contact 24 includes a base portion 25, a pair of forks 26 extending from the base portion 25 substantially in parallel with each other, and a terminal 27 extending from the base portion substantially perpendicular to each fork 26. The terminal 27 is fixed to the printed circuit board by soldering. Each fork 26 has a substantially triangular projection 28 formed on a side thereof. The projections 28 are used to fix the contact 24 to the housing 22 by press-in.
When the insulation displacement plug 10 is fitted in the chamber 21 of the printed board connector 20, the contact portion 15 of the insulation displacement contact 12 is held between the pair of forks 26 of the contact 24. The contact between the insulation displacement contact 12 and the contact 24 allows an electrical connection between the cable 17 connected to the insulation displacement plug 10 and the printed circuit board.
In the case of using a mating instrument such as the one described above, a reflow soldering device is often used to mount a printed board connector in a printed circuit board. However, during reflow soldering, surface tension of the solder may cause solder and/or flux to rise from the terminals to the pair of forks.
That is, if the printed board connector 20 is to be fixed to a printed circuit board, the bottom surface of the terminal 27 (FIG. 7) of the connector 20 is soldered to a predetermined location of the printed circuit board, as described above. At this time, solder (solder alloy) and/or flux supplied to the terminal 27 may rise beyond the base portion 25 and reach the forks 26, extending substantially perpendicular to the terminal 27. If the solder rises to the tips of the forks 26, it may degrade the spring property of the forks 26. Further, if the flux rises to the tips of the forks 26, it may deteriorate an electrical conductivity between the insulation displacement contact 12 and the contact 24.
The present invention is aimed to overcome the above-described problems and provides a printed board connector, a contact thereof, and a mating instrument that can prevent solder rising and/or flux rising so as to improve the reliability of the electric conductivity between contacts and the spring property of the contacts.
A first aspect of the present invention relates to a printed board connector capable of being mounted in a printed circuit board. This connector comprises a housing and a contact arranged in the housing. The contact includes a pair of forks opposing each other, a terminal capable of being soldered to the printed circuit board, and a spacer connecting the terminal and the pair of forks together. The spacer provides a predetermined distance between the terminal and the pair of forks to prevent solder and/or flux from rising to the forks. Accordingly, the present invention improves the reliability of the electric conductivity and the spring property of the contact.
In this specification, the xe2x80x9csolderxe2x80x9d essentially means both conventional tin/lead solder (Sn/Pb solder) and lead-free solder such as Sn/Ag solder.
Preferably, the spacer defines a predetermined interval between the terminal and the root of the pair of forks. This is achieved by providing the spacer with at least one folded portion. This configuration effectively prevents the solder rising and/or flux rising toward the forks.
Preferably, the terminal extend substantially perpendicular to the pair of forks. This enables another connector to engage with the printed board connector mounted in the printed circuit board, from over the printed circuit board.
Preferably, the spacer includes a base portion, a first intermediate portion, a turn-up portion and a second intermediate portion. The base portion is connected to the pair of forks. The first intermediate portion extends substantially in parallel with the forks from an end of the base portion. The end is opposite the forks. The turn-up portion is connected to the first intermediate portion. The second intermediate portion connects the turn-up portion and the terminal together. The second intermediate portion is farther from the pair of forks than the first intermediate portion. That is, the first intermediate potion is positioned between the forks and the second intermediate portion. In this configuration, solder essentially rises along a rear surface of the second intermediate portion, which is kept away from the forks. Consequently, the solder can be easily kept away from the forks.
Preferably, spaces are defined between the base portion and the terminal and between the first intermediate portion and the second intermediate portion. These spaces allow solder, which is supplied between the terminal and the printed circuit board and is likely to travel toward the forks, to be kept away from the forks.
Preferably, the second intermediate portion is branched in two directions, and the contact has two terminals connected to each branched portion of the second intermediate portion respectively. In this configuration, a predetermined interval is defined between the two terminals. The intervals (areas) allow solder to be kept away from forks.
Another aspect of the present invention provides a contact for a printed board connector. The contact comprises a pair of forks opposing each other, a terminal capable of being soldered to the printed circuit board, and a spacer connecting the terminal and the pair of forks. The spacer provides a predetermined distance between the terminal and the pair of forks to prevent solder and/or flux from rising to the forks.
A still another aspect of the present invention provides a mating instrument comprising a male connector and a female connector. The male connector has a contact portion. The female connector has a housing with a chamber which receives the male connector, and a contact arranged in the housing. The contact of the female connector includes a pair of forks opposing each other and capable of holding the contact portion of the male connector therebetween, a terminal capable of being soldered to the printed circuit board, and a spacer connecting the terminal and the pair of forks together. The spacer provides a predetermined distance between the terminal and the pair of forks to prevent solder and/or flux from rising to the forks.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.